Retracting Sheath Detachable Safety Needle with Moving Spring

ABSTRACT

A passive safety needle device is disclosed having a housing, a needle hub, a needle cannula, a retractable sheath, a spring to bias the retractable sheath in a distal direction to cover the distal end of the needle cannula, a radial protrusion to cause the spring to move from the proximal spring position to the distal spring position, and a catch to secure the distal end of the spring to the distal end of the housing. The spring may bias the retractable sheath in a distal direction to cover the distal end of the needle cannula. The radial protrusion causes the spring to move from a proximal spring position to the distal spring position towards the catch located at the distal end of the housing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/793,655, filed Mar. 11, 2013, which claims priority under 35 U.S.C.§119(e) to U.S. Provisional Application No. 61/610,623, filed Mar. 14,2012, the disclosures of which are incorporated herein by reference intheir entirety.

TECHNICAL FIELD

The subject invention relates generally to a safety needle device, andmore particularly to a passive safety needle device having a housing, aneedle hub, a needle cannula, a retractable sheath, a spring to bias theretractable sheath in a distal direction to cover the distal end of theneedle cannula, a radial protrusion to cause the spring to move from theproximal spring position to the distal spring position, and a catch tosecure the distal end of the spring to the distal end of the housing.The radial protrusion causes the spring to move from a proximal springposition and a distal spring position separated by a ledge towards thecatch located at the distal end of the housing.

BACKGROUND

Needle devices are used throughout the medical industry for theinjection and withdrawal of a wide variety of fluids and solutions intoand from the human body. Because of the numerous potential hazardsassociated with the handling and manipulation of bodily fluids, andparticularly blood, there are a number of known safety features that arefrequently incorporated into various types of needle devices to protectthe practitioner from accidental exposure to the needle.

Other prior safety needle devices having a retractable sheath requiremulti-component retraction and locking elements. Conventional retractionsyringe assemblies often do not incorporate reuse prevention features,and thus, the retraction mechanism may be reset so the syringe barrelmay be reused. The reuse of syringe assemblies without sterilization orsufficient sterilization is believed to facilitate the transfer ofcontagious diseases. Further, the retraction features of conventionalsyringes also often require the user to actively activate the retractionmechanism. Accordingly, the chance of human error in failure to activateor properly activate the retraction mechanism can lead to continuedexposure of needles.

Prior retracting sheath safety needle devices have been developed toinclude a single-use cover assembly that obscures a substantial majorityor an entirety of an injection needle from view before, during, andafter an injection procedure. However, many injection procedures requirethat the practitioner know precisely the location and depth to which theneedle is inserted in the patient's tissue to be sure that medication isdelivered to an appropriate location.

There is a need in the art to provide a safety needle device having apassive activation mechanism that overcomes the deficiencies of theknown retracting sheath safety needle devices and which allows for lowpart count, low part complexity, clear and unobstructed view of needlethrough sheath, relatively compact design and no rotation of the sheathduring use.

SUMMARY

The present invention is directed to a safety needle device including ahousing, a needle hub, a needle cannula, a retractable sheath, a springto bias the retractable sheath in a distal direction to cover the distalend of the needle cannula, a radial protrusion to cause the spring tomove from the proximal spring position to the distal spring position,and a catch to secure the distal end of the spring to the distal end ofthe housing. The housing includes a proximal end and a distal end havingan opening. In one or more embodiments, the proximal end of the housingmay be connectable to a luer connection or other fluid connector.

The retractable sheath may be disposed and movable in the opening andsurrounds a needle cannula having a distal end and a proximal end. Theneedle cannula is mounted to a needle hub at the proximal end of thehousing. The retractable sheath includes a radially enlarged proximalend defining a proximal spring position and a distal spring positionseparated by a ledge.

The spring may bias the retractable sheath in a distal direction tocover the distal end of the needle cannula. The spring includes aproximal end, a main body, and a distal end. In one embodiment, theradial protrusion may extend inwardly into housing to cause the springto move from the proximal spring position to the distal spring positionso that when the spring is extended, the distal end of the spring issecured to a catch at the distal end of the housing.

In one or more embodiments, the spring comprises a compression or coilspring having an enlarged coil portion on the distal end that has adiameter larger than the proximal end and main body of the spring. Inone or more embodiments, the enlarged coil portion rests on the ledgewhen the spring is in the proximal spring position. In one or moreembodiments, the enlarged coil portion rests on the catch to lock theretractable sheath when the spring is in the distal spring position.

In one or more embodiments, the catch is defined by inward rampsterminating in barbed ends.

In one or more embodiments, the retractable sheath fully covers theneedle when the spring is in the distal spring position.

In one or more embodiments, the radial protrusion is configured toprovide free movement between the radial protrusion and the proximal endand main body of the spring. In one or more embodiments, the radialprotrusion is configured to provide hindered movement between the radialprotrusion and the enlarged coil portion. In one or more embodiments,the radial protrusion compresses the enlarged coil portion to cause theenlarged coil portion to slip from the ledge and move from the proximalspring position to the distal spring position. In some embodiments, theradial protrusion is located on the proximal end of the housing. Inother embodiments, the radial protrusion is located on the distal end ofthe housing.

The present invention is also directed to a safety needle deviceincluding a housing having a proximal end and a distal end having anopening; a needle cannula having a distal end and a proximal end mountedto a needle hub at the proximal end of the housing; a retractable sheathdisposed an outer surface on the distal end of the housing surroundingthe needle cannula, the retractable sheath having a larger diameter thanthe housing and having a radially enlarged proximal end defining aproximal spring position and a distal spring position separated by aledge; a spring to bias the retractable sheath in a distal direction tocover the distal end of the needle cannula, the spring having a distalend; and a radially compressible member on the distal end of the springhaving a larger diameter than the proximal end and main body of thespring; and a radially protrusion extending outwardly from housing tocause the radially compressible member to compress upon an applicationof force in the proximal direction to allow the spring to move from theproximal spring position to the distal spring position so that when thespring is extended, the distal end of the spring is secured to a catchat the distal end of the housing. In one or more embodiments, theproximal end of the housing may be connectable to a luer connection orother fluid connector.

In one or more embodiments, the radially compressible member rests onthe ledge when the spring is in the proximal spring position. In one ormore embodiments, the radially compressible member rests on the catch tolock the retractable sheath when the spring is in the distal springposition.

The present invention is also directed to a safety needle deviceincluding a housing having a proximal end and a distal end having anopening; a needle cannula having a distal end and a proximal end mountedto a needle hub at the proximal end of the housing; a needle hub havinga radial protrusion extending outward into housing and a distal endhaving a ramped surface; a retractable sheath having a proximal end anddistal end, the proximal end having a first flange forming a ledge withthe ramped surface of the needle hub and a second flange to hold theretractable sheath in the housing, the retractable sheath surrounding aneedle cannula having a distal end and a proximal end mounted to theneedle hub at the proximal end of the housing, the first and secondflange defining a proximal spring position and a distal spring position;a spring to bias the retractable sheath in a distal direction to coverthe distal end of the needle cannula, the spring having a proximal end,a main body, and a distal end; the radially protrusion causing thespring to move from the proximal spring position to the distal springposition when the spring is extended; and a catch forming between theramped surface and the second flange of the retractable sheath. In oneor more embodiments, the proximal end of the housing may be connectableto a luer connection or other fluid connector.

In one or more embodiments, the spring comprises a reduced coil portionon the distal end having a smaller diameter than the proximal end andmain body of the spring. In one or more embodiments, the reduced coilportion rests on the ledge when the spring is in the proximal springposition. In one or more embodiments, the reduced coil portion rests onthe catch to lock the retractable sheath when the spring is in thedistal spring position.

In one or more embodiments, the catch is defined by a recess formedbetween the outward ramped surface of the needle hub and the secondflange of the retractable sheath.

In one or more embodiments, the radial protrusion is configured toprovide free movement between the radial protrusion and the proximal endand main body of the spring. In one or more embodiments, the radialprotrusion is configured to provide hindered movement between the radialprotrusion and the reduced coil portion. In one or more embodiments, theradial protrusion enlarges the reduced coil portion to cause the reducedcoil portion to slip from the ledge and move from the proximal springposition to the distal spring position. In one or more embodiments, theradial protrusion is located proximally to the ledge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the safety needle device.

FIG. 2 is a plan view of the safety needle device.

FIG. 3 is a plan view of the slots and rails of the safety needledevice.

FIG. 4 is a perspective view of the spring of the safety needle devicehaving an enlarged end coil.

FIG. 5 is a plan view of the safety needle device prior to activation.

FIG. 6 is another plan view of the safety needle device prior toactivation.

FIG. 7 is another plan view of the safety needle device prior toactivation.

FIG. 8 is a plan view of the safety needle device after activation.

FIG. 9 is a plan view of the safety needle device after activation atthe bottom of travel.

FIG. 10 is a plan view of the safety needle device after activationshowing enlarged end coil section locked in catch.

FIG. 11 is a plan view of the safety needle device in accordance with analternative embodiment of the present invention.

FIG. 12 is a plan view of the safety needle device in accordance withyet another alternative embodiment of the present invention.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the invention, it isto be understood that the invention is not limited to the details ofconstruction or process steps set forth in the following description.The invention is capable of other embodiments and of being practiced orbeing carried out in various ways.

In this disclosure, a convention is followed wherein the distal end ofthe device is the end closest to a patient and the proximal end of thedevice is the end away from the patient and closest to a practitioner.

FIGS. 1-10 illustrate an exemplary safety needle device 10 according tothe present invention. Safety needle device 10 including a housing 20, aneedle hub 30, a needle 40, a retractable sheath 50, a spring 60 to biasthe retractable sheath 50 in a distal direction to cover the distal endof the needle 40, a radial protrusion 70 to cause the spring 60 to movefrom the proximal spring position 80 to the distal spring position 90,and a catch 100 to secure the distal end of the spring 60 to the distalend of the housing 20. In one or more embodiments, the housing 20includes a proximal end 22 and a distal end 24 having an opening.

Generally speaking, safety needle device 10 is comprised of a needle 40,a housing 20, and a retractable sheath 50. Housing 20 includes aproximal end 22 and a distal end 24 having an opening. In one or moreembodiments, the proximal end of the housing may be connectable to aluer connection or other fluid connector. Retractable sheath 50 isslidably mounted and movable in the opening to slidably accommodate andencase needle 40 projecting axially from housing 20. The term“retractable sheath” is intended to include any sort of tubular memberand U-shaped member. The retractable sheath 50 is dimensioned to becompatible with the size and type of needle 40 as will be appreciated bythose skilled in the art. The housing 20 may include a housing bodyportion with an internal hollow region (not shown) in which theretractable sheath 50 may move in the proximal direction. As shown inFIG. 2, needle 40 may be connected to a needle hub 30 disposed at theproximal end 22 of the housing 20 and having a blunted tip or beveledtip at the distal end. The needle 40 is disposed in the needle hub 30 ina manner as would be well understood in the art and which forms no partof the invention. The needle hub 30 may be integrally formed with thehousing 20. The needle 40 extends from the needle hub 30 disposed in thehousing 20 to a needle tip and is completely received within theretractable sheath 50 when the retractable sheath 50 is in a distalposition. The needle tip is exposed from the retractable sheath 50 whenthe retractable sheath 50 is in a proximal position. FIG. 3 shows theinternal slots and rails of the safety device.

As illustrated in several of the drawings, most notably FIGS. 1 and 2,retractable sheath 50 is generally comprised of a tubular portion and isretractably slidable along the length of the needle 40 such that atleast a substantial portion of needle 40 is exposed when the sheath 50is in its retracted position (as illustrated in FIG. 2). The length ofneedle 40 extending outwardly from the needle hub 30 in a distaldirection is partially or completely encased when retractable sheath 50is in its non-retracted position (as illustrated in FIGS. 1 and 2).

The needle 40 in accordance with the present invention can be formedfrom conventional materials such as steel or more preferably stainlesssteel. It will be realized by the skilled artisan that medical gradeplastics, composites, ceramics, or like materials can be substituted.

The inside diameter of the open-ended retracting sheath 50 is selectedso that it will fit closely over needle 40. The retracting sheath 50 maybe made of any suitable material, but preferably of a polymer which istough enough to protect needle 40 and may be easily sterilized. Thematerial is preferably transparent or translucent so that the positionof needle 40 within retracting sheath 50 can be visually verified.Sheath 50 is preferably made of a transparent material, so that a healthcare worker can see the progress of needle 40 as it is emerging fromsheath 50 to make sure that it is positioned where desired for aninjection.

The retractable sheath 50 may be disposed and movable in the opening andsurrounds a needle 40 having a distal end and a proximal end. The needle40 is mounted to a needle hub 30 at the proximal end of the housing. Theretractable sheath 50 includes a radially enlarged proximal end defininga proximal spring position 80 and a distal spring position 90 separatedby a ledge 150. The retractable sheath 50 is spring loaded, and issupplied with the sheath completely or partially covering the needle 40.

The spring 60 may bias the retractable sheath 50 in a distal directionto cover the distal end of the needle 40. The spring 60 includes aproximal end, a main body, and a distal end. In one embodiment, theradial protrusion 70 may extend inwardly into housing 20 to cause thespring 60 to move from the proximal spring position 80 to the distalspring position 90 so that when the spring 60 is extended, the distalend of the spring 60 is secured to a catch 100 at the distal end of thehousing. In this position, the spring impedes proximal movement of theretracting sheath, thereby protecting the needle tip.

In one or more embodiments, as shown in FIG. 4, the spring 60 comprisesa compression or coil spring having an enlarged end coil 130 on thedistal end that has a diameter larger than the proximal end and mainbody of the spring 60 which is of a constant or smaller diameter, asshown in FIGS. 4 and 5. In one or more embodiments, as shown in FIGS. 5and 6, the enlarged coil portion rests on the ledge 150 when the spring60 is in the proximal spring position 80. In one or more embodiments,the enlarged coil portion rests on the catch 100 to lock the retractablesheath 50 when the spring is in the distal spring position 90, and theretractable sheath is in the distal position of the housing.

In one or more embodiments, the catch 100 is defined by inward rampsterminating in barbed ends.

In one or more embodiments, the retractable sheath 50 fully covers theneedle 40 when the spring is in the distal position of the housing.

In one or more embodiments, the radial protrusion 70 is configured toprovide free movement between the radial protrusion 70 and the proximalend and main body of the spring 60. In one or more embodiments, theradial protrusion 70 is configured to provide hindered movement betweenthe radial protrusion 70 and the enlarged end coil 130. In one or moreembodiments, as shown in FIGS. 7 and 8, the radial protrusion 70compresses the enlarged end coil 130 to cause the enlarged end coil 130to slip from the ledge 150 and move from the proximal spring position 80to the distal spring position 90. In some embodiments, the radialprotrusion 70 is located on the proximal end of the housing. In otherembodiments, the radial protrusion 70 is located on the distal end ofthe housing.

Upon administration of the injection, the retractable sheath 50 movesfrom a distal to proximal position and the needle tip is exposed so thatthe needle tip may penetrate the injection site. Upon continuedapplication of force by pressing sheath 50 against the skin at thelocation where it is desired to insert needle 40, sheath 50 retractsinto housing 20 allowing the injection site to be penetrated by theneedle tip. As shown in FIG. 3, the enlarged end coil 130 is retained onthe ledge 150 and cannot lock on the catch, and therefore theretractable sheath 50 is not locked into place.

As shown in FIG. 5, there is a clearance between the radial protrusion70 and the main body of the spring 60. As shown in FIG. 7, the radialprotrusion 70 is sized such that it will interfere with the enlarged endcoil 130 as it passes over causing the enlarged end coil 130 to becompressed by the radial protrusion 70. As shown in FIG. 8, uponcontinued application of proximal force, the enlarged end coil 130 iscompressed and becomes too small to be retained on the ledge 150,thereby slipping off the ledge 150. The radial protrusion 70 can beplaced at any point in the housing 20 such that activation, whereby theretractable sheath 50 will lock if the safety needle device 10 is pulledout, can occur either at a very distal point in the housing, near thebeginning of the stroke as soon as the coil clears the barbs in thehousing, or at a proximal point in the housing, for example, the bottomof the stroke, as shown in FIG. 9, when the needle 40 is fully insertedinto the injection site, or at any position along the length of thehousing. As shown in FIG. 10, as the injection is completed and theneedle 40 is pulled from injection site, the spring force causes thesheath 50 to extend, and at the end of the stroke, the enlarged end coil130 advances past the catch 100 at the end of the stroke to lock theretractable sheath 50 thereby completing a passive safety lock-out.

Constant Diameter Spring with Radially Compressible Member

In another embodiment of the present invention, it is envisioned thatthe spring 60 has a constant diameter having a radially compressiblemember 160, for example C-clip, attached to or biased against its distalend wherein the radially compressible member 160 rests on a ledge 150.

As shown in FIG. 11, the present invention is also directed to a safetyneedle device including a housing 20 having a proximal end and a distalend having an opening; a needle 40 having a distal end and a proximalend mounted to a needle hub 30 at the proximal end of the housing; aretractable sheath 50 disposed an outer surface on the distal end of thehousing 20 surrounding the needle 40, the retractable sheath 50 having aradially enlarged proximal end defining a proximal spring position 80and a distal spring position 90 separated by a ledge 150; a spring 60 tobias the retractable sheath 50 in a distal direction to cover the distalend of the needle 40, the spring 60 having a distal end; and a radiallycompressible member on the distal end of the spring 60 having a largerdiameter than the proximal end and main body of the spring 60; and aradial protrusion 70 extending inwardly from the housing 20 to cause theradially compressible member to compress upon an application of force ormotion in the proximal direction to allow the radially compressiblemember to move from a proximal position to the distal position so thatwhen the spring is extended, the radially compressible member is securedto a catch 100 at the distal end of the housing. In one or moreembodiments, the proximal end of the housing may be connectable to aluer connection or other fluid connector, or integrated into a device,such as a syringe.

Upon administration of an injection, proximally directed force resultsin the radially compressible member progressing to the radial protrusion70 extending outwardly from housing. After reaching the radialprotrusion 70, continued proximally directed force results in thecompression of the radially compressible member allowing the compressedradially compressible member to slip off the ledge 150 causing thecompressible member to advance from a proximal to distal position in thehousing. As the compressible member advances from a proximal to distalposition in the housing, the radially compressible member advances pastthe catch 100 to lock the retractable sheath 50 completing a passivesafety lock-out.

In one or more embodiments, the radially compressible member rests onthe ledge 150 when the member is in the proximal position. In one ormore embodiments, the radially compressible member rests on the catch100 to lock the retractable sheath 50 when the member is in a distalposition, and the retractable sheath is in the distal position of thehousing.

Internal configuration with Reduced End Coil Spring

In another embodiment of the present invention, it is envisioned thatthe internal locking components may be inverted so that the springactivates and locks on component features on the inside of the spring,rather than outside of its coils. In such an embodiment, a needle hub 30extending to the tip of the housing 20 includes radial outwardprotrusion, locking barb, and ledge 150 that interact with a shrunkenend coil on the inside of the spring.

As shown in FIG. 12, the present invention is also directed to a safetyneedle device 10 including a housing 20 having a proximal end and adistal end having an opening; a needle 40 having a distal end and aproximal end mounted to a needle hub 30 at the proximal end of thehousing; a needle hub 30 having a radial protrusion 70 extending outwardinto housing 20 and a distal end having a ramped surface; a retractablesheath 50 having a proximal end and distal end, the proximal end havinga first flange 110 forming a ledge 150 with the ramped surface of theneedle hub 30 and a second flange 120 to hold the retractable sheath 50in the housing, the retractable sheath 50 surrounding a needle 40 havinga distal end and a proximal end mounted to the needle hub 30 at theproximal end of the housing, the first and second flange 120 defining aproximal spring position 80 and a distal spring position 90; a spring tobias the retractable sheath 50 in a distal direction to cover the distalend of the needle 40, the spring having a proximal end, a main body, anda distal end; the radial protrusion causing the spring to move from theproximal spring position 80 to the distal spring position 90 when thespring is extended; and a catch 100 forming at the distal end of theramped surface between the ramped surface and the second flange 120 ofthe retractable sheath 50.

In one or more embodiments, the spring comprises a reduced end coil 140on the distal end having a smaller diameter than the proximal end andmain body of the spring. In one or more embodiments, the reduced endcoil 140 rests on the ledge 150 when the spring is in the proximalspring position 80. In one or more embodiments, the reduced end coil 140rests on the catch 100 to lock the retractable sheath 50 when the springis in the distal spring position 90.

In one or more embodiments, the catch 100 is defined by a recess formedbetween the outward ramped surface of the needle hub 30 and the secondflange 120 of the retractable sheath 50.

In one or more embodiments, the radial protrusion 70 is configured toprovide free movement between the radial protrusion 70 and the proximalend and main body of the spring. In one or more embodiments, the radialprotrusion 70 is configured to provide hindered movement between theradial protrusion 70 and the reduced end coil 140. In one or moreembodiments, the radial protrusion 70 enlarges the reduced end coil 140to cause the reduced end coil 140 to slip from the ledge 150 and movefrom the proximal spring position 80 to the distal spring position 90.In one or more embodiments, the radial protrusion 70 is locatedproximally to the ledge 150.

In one or more embodiments, the proximal end of the housing may beconnectable to a luer connection or other fluid connector, or integratedinto a device, such as a syringe.

Upon administration of the injection, the retractable sheath 50 movesfrom a distal to proximal position and the needle tip is exposed so thatthe needle tip may penetrate the injection site. Upon continuedapplication of force by pressing sheath 50 against the skin of a patientat the location where it is desired to insert needle 40, sheath 50retracts into housing 20 allowing the injection site to be penetrated bythe needle. As shown in FIG. 12, the reduced end coil 140 is retained onthe ledge 150 and cannot lock on the catch, and therefore theretractable sheath 50 is not locked into place.

As shown in FIG. 12, there is a clearance between the radial protrusion70 and the main body of the spring. As shown in FIG. 12, the radialprotrusion 70 is sized such that it will interfere with the reduced endcoil 140 as it passes over causing the reduced end coil 140 to beexpand. As shown in FIG. 12, upon continued application of proximalforce, the reduce end coil is expanded and becomes too large to beretained on the ledge 150, thereby slipping off the ledge 150. Theradial protrusion 70 can be placed at any point in the housing 20 suchthat activation, whereby the retractable sheath 50 will lock if thesafety needle device 10 is pulled out, can occur either at a very distalpoint in the housing, near the beginning of the stroke as soon as thecoil clears the barbs in the housing, or at a proximal point in thehousing, for example, the bottom of the stroke when the needle 40 isfully inserted into the injection site, or at any position along thelength of the housing. Upon continued application of proximal force asthe injection is completed, reduced end coil 140 extends past the rampedsurface and advances into the catch 100 at the end of the stroke to lockthe retractable sheath 50 thereby completing a passive safety lock-out.

In yet another embodiment, an orientation similar to the one describedherein for internal configuration with reduced end coil spring is alsoenvisioned using the constant diameter spring with radially compressiblemember.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe invention. Thus, the appearances of the phrases such as “in one ormore embodiments,” “in certain embodiments,” “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the invention.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present invention without departing from the spirit andscope of the invention. Thus, it is intended that the present inventioninclude modifications and variations that are within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A safety needle device comprising: a housinghaving a proximal end and a distal end having an opening; a needlecannula having a distal end and a proximal end mounted to a needle hubat the proximal end of the housing; a retractable sheath disposed anouter surface on the distal end of the housing surrounding the needlecannula, the retractable sheath having a larger diameter than thehousing and having a radially enlarged proximal end defining a proximalspring position and a distal spring position separated by a ledge; aspring to bias the retractable sheath in a distal direction to cover thedistal end of the needle cannula, the spring having a distal end; and aradially compressible member at the distal end of the spring having alarger diameter than the proximal end and main body of the spring; and aradial protrusion extending inwardly from the housing to cause theradially compressible member to compress upon an application of force inthe proximal direction to allow the spring to move from a proximalposition to a distal position so that when the spring is extended, thedistal end of the radially compressible member is secured to a catch atthe distal end of the housing.
 2. The safety needle device of claim 1,wherein the radially compressible member rests on the ledge when themember is in the proximal position.
 3. The safety needle device of claim1, wherein the radially compressible member rests on the catch to lockthe retractable sheath when the member is in the distal position and thesheath is in the distal position.
 4. The safety needle device of claim1, wherein the catch is defined by inward ramps optionally terminatingin barbed ends.
 5. The safety needle device of claim 1, wherein theradial protrusion is configured to provide free movement between theradial protrusion and the proximal end and main body of the spring. 6.The safety needle device of claim 1, wherein the radial protrusioncompresses the radially compressible member to cause the radiallycompressible member to slip from the ledge and move from the proximalspring position to the distal spring position.
 7. A safety needle devicecomprising: a housing having a proximal end and a distal end having anopening; a needle cannula having a distal end and a proximal end mountedto a needle hub at the proximal end of the housing; a needle hub havinga radial protrusion extending outward into housing and a distal endhaving a ramped surface; a retractable sheath having a proximal end anddistal end, the proximal end having a first flange forming a ledge withthe ramped surface of the needle hub and a second flange to hold theretractable sheath in the housing, the retractable sheath surrounding aneedle cannula having a distal end and a proximal end mounted to theneedle hub at the proximal end of the housing, the first and secondflange defining a proximal spring position and a distal spring position;a spring to bias the retractable sheath in a distal direction to coverthe distal end of the needle cannula, the spring having a proximal end,a main body, and a distal end; the radial protrusion causing the springto move from the proximal spring position to the distal spring positionwhen the spring is extended; and a catch forming at the distal end ofthe ramped surface and the second flange of the retractable sheath. 8.The safety needle device of claim 7, wherein the spring comprises areduced coil portion on the distal end having a smaller diameter thanthe proximal end and main body of the spring.
 9. The safety needledevice of claim 8, wherein the reduced coil portion rests on the ledgewhen the spring is in the proximal spring position.
 10. The safetyneedle device of claim 9, wherein the reduced coil portion rests on thecatch to lock the retractable sheath when the spring is in the distalspring position and the sheath is in distal position.
 11. The safetyneedle device of claim 7, wherein the catch is defined by a recessformed between the outward ramped surface of the needle hub and thesecond flange of the retractable sheath.
 12. The safety needle device ofclaim 7, wherein the radial protrusion is configured to provide freemovement between the radial protrusion and the proximal end and mainbody of the spring.
 13. The safety needle device of claim 7, wherein theradial protrusion enlarges the reduced coil portion to cause the reducedcoil portion to slip from the ledge and move from the proximal springposition to the distal spring position.